This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present invention, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present invention. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
A variety of industrial and commercial applications use natural gas as a source of power and/or heat. For instance, a combustion engine may use natural gas to provide mechanical power to drive wheels, electrical generators, and other machinery. A furnace or appliance (e.g., a laundry machine) may use natural gas as a source of heat. A manufacturing process may use natural gas in the manufacture of an array of products and materials, including glass, steel, and plastics, for example. Thus, a high demand exists for natural gas. Companies often spend a significant amount of time and resources in the search, extraction, and transportation of natural gas. For example, equipment may extract natural gas from an oil field, and transport the natural gas to a remote facility. Typically, the equipment includes a compressor to facility the transportation process.
A reciprocating compressor is one type of compressor that is suitable for such applications, among others. A reciprocating compressor is a positive-displacement device, which utilizes a motor to drive one or more pistons via a crankshaft and connecting rods. Each piston reciprocates back and forth in a cylinder to intake a gas into a chamber, compress the gas within the chamber, and exhaust the gas from the chamber to a desired output. Unfortunately, existing reciprocating compressors are prone to leakage of the gas into internal components, e.g., the crankshaft. Such leakage causes undesirable corrosion and wear of the internal components.
One leakage reduction technique involves the use of seals and packing assemblies. For example, existing reciprocating compressors include multiple seals and packing assemblies to block the gas in the chamber from leaking into other internal components, e.g., the crankshaft. Such seals and packing assemblies are typically mounted around the piston's rod. Unfortunately, these seals and packing assemblies are prone to leakage, which generally increases with wear of the reciprocating compressor. Furthermore, these seals and packing assemblies add friction and, thus, heat to the moving components. As a result, the packing assemblies generally require a lubrication system and a cooling system, which adds further to the technical challenge, cost, and size to the reciprocating compressors.
Another leakage reduction technique involves the use of an intermediate section between the crankshaft and the pistons. The intermediate section (known as an auxiliary distance piece) may be pressurized to resist leakage of the gas into the internal components of the reciprocating compressor. The intermediate section also may be purged to release leaked gas. Unfortunately, the intermediate section cannot completely prevent gas from leaking into the internal components of the reciprocating compressor. The intermediate section also increases the size, weight, and potential vibration of the reciprocating compressor. For example, the intermediate section results in a larger footprint of the reciprocating compressor, a longer connecting rod between the crankshaft and each piston, and so forth.